Preparation and Properties of La2/3Sr1/3MnO3: Agx Polycrystalline Composites

2012 ◽  
Vol 519 ◽  
pp. 45-48 ◽  
Author(s):  
Yi Zhi Yan ◽  
Xiang Liu ◽  
Qing Ming Chen ◽  
Shao Chun Zhang
Keyword(s):  
High Temperature ◽  
Room Temperature ◽  
Precipitation Method ◽  
X Ray Diffraction ◽  
X Ray ◽  
Maximum Value ◽  
Measurement Results ◽  
Z Value ◽  
And Performance ◽  
Co Precipitation

La2/3Sr1/3MnO3: Agx (LSMO: Agx) polycrystalline composites were prepared by co-precipitation method. Structure and performance of La2/3Sr1/3MnO3: Agx were investigated by X ray diffraction and R-T measurement. Results show that, all samples are perovskite structure. With the addition of Ag increased, the volume and conductivity of LSMnO: Agx were increased accordingly. The resistivity of the samples (x=0.30, 0.40) is only 10% of the pristine. The TCR of LSMO: Agx (x=0.3) is obtained maximum value of 3.39% as the Z value 0.50. It’s perhaps the proper candidate material to be high temperature electrode or near room temperature bolometer and infrared devices.

Preparation and Electrochemical Performance of Mn3O4/GR Composites Electrode Material in Supercapacitors

2019 ◽  
Vol 807 ◽  
pp. 50-56
Author(s):  
Yun Long Zhou ◽  
Zhi Biao Hu ◽  
Li Mei Wu ◽  
Jiao Hao Wu
Keyword(s):  
Room Temperature ◽  
Raw Materials ◽  
Precipitation Method ◽  
Electrochemical Performances ◽  
Manganese Sulfate ◽  
X Ray Diffraction ◽  
X Ray ◽  
Co Precipitation ◽  
A Current ◽  
Discharge Test

Using hydrated manganese sulfate and general type graphene (GR) as raw materials, Mn3O4/GR composite has been successfully prepared by the liquid phase chemical co-precipitation method at room temperature. X-ray diffraction (XRD) was used to investigate the phase structure of Mn3O4powder and Mn3O4/GR composite; The electrochemical performances of the samples were elucidated by cyclic voltammetry and galvanostatic charge-discharge test in 0.5 mol/L Na2SO4electrolyte. The results show that the Mn3O4/GR composite possesses graphene phase and good reversibility; the composite also displays a specific capacitance of 318.8 F/g at a current density of 1 A/g.

scholarly journals Crystal Chemistry and Luminescence Properties of Eu-Doped Polycrystalline Hydroxyapatite Synthesized by Chemical Precipitation at Room Temperature

Crystals ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 250 ◽  
Author(s):  
Francesco Baldassarre ◽  
Angela Altomare ◽  
Nicola Corriero ◽  
Ernesto Mesto ◽  
Maria Lacalamita ◽  
...  
Keyword(s):  
Fourier Transform ◽  
High Temperature ◽  
Inductively Coupled Plasma ◽  
Room Temperature ◽  
Annealing Temperature ◽  
Chemical Precipitation ◽  
Precipitation Method ◽  
X Ray Diffraction ◽  
X Ray ◽  
Inductively Coupled

Europium-doped hydroxyapatite Ca10(PO4)6(OH)2 (3% mol) powders were synthesized by an optimized chemical precipitation method at 25 °C, followed by drying at 120 °C and calcination at 450 °C and 900 °C. The obtained nanosized crystallite samples were investigated by means of a combination of inductively coupled plasma (ICP) spectroscopy, powder X-ray diffraction (PXRD), Fourier Transform Infrared (FTIR), Raman and photoluminescence (PL) spectroscopies. The Rietveld refinement in the hexagonal P63/m space group showed europium ordered at the Ca2 site at high temperature (900 °C), and at the Ca1 site for lower temperatures (120 °C and 450 °C). FTIR and Raman spectra showed slight band shifts and minor modifications of the (PO4) bands with increasing annealing temperature. PL spectra and decay curves revealed significant luminescence emission for the phase obtained at 900 °C and highlighted the migration of Eu from the Ca1 to Ca2 site as a result of increasing calcinating temperature.

Synthesis and Gas Sensing Properties of SnO2-CuO Nanocomposites

2013 ◽  
Vol 645 ◽  
pp. 129-132 ◽  
Author(s):  
Jantasom Khanidtha ◽  
Suttinart Noothongkaew ◽  
Supakorn Pukird
Keyword(s):  
Room Temperature ◽  
Gas Sensing ◽  
Precipitation Method ◽  
Monoclinic Structure ◽  
X Ray Diffraction ◽  
Sem Images ◽  
X Ray ◽  
Sensing Properties ◽  
Gas Sensing Properties ◽  
Co Precipitation

SnO2-CuO nanocomposites have been synthesized with the simple co-precipitation method for gas sensing properties. Sn and CuO powder were the starting materials. The synthesized products were investigated by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The results show that SnO2-CuO nanocomposites have a tetragonal and monoclinic structure, respectively. SEM images verify that the some microballs are up to 10 µm and nanorods have a diameter range from 10-100 nm, while length ranges a few micrometers. The nanocomposite products were highly sensitivity to CO2gas at room temperature.

scholarly journals A Study of Photocatalytic Degradation of Betalain Pigment from Kitchen Waste, Semiconductive Nanostructured TiO2 Used as a Photocatalyst

2018 ◽  
Vol 15 (3) ◽  
pp. 272-278
Author(s):  
G. Muthukumar ◽  
B Arjunkumar ◽  
R. Vignesh ◽  
G. Ramalingam
Keyword(s):  
Beta Vulgaris ◽  
Room Temperature ◽  
Precipitation Method ◽  
Polluted Water ◽  
Tio2 Powder ◽  
X Ray Diffraction ◽  
Kitchen Waste ◽  
X Ray ◽  
Co Precipitation ◽  
Betalain Pigment

Well crystallinenanostructured TiO2 powder was synthesised by Co-precipitation method using Titanium (IV) isopropoxide and CTAB are precursor materialsto maintain in 1:1 ratio concentration. The synthesised power was structurally, morphologically and optically analysed to using X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM) and UV-Vis absorption spectra. The betalain pigment of polluted water was prepared from Beta vulgaris extract at room temperature (RT). The 89% of betalain pigment was degraded at 40 min from Beta vulgaris extract polluted water using as-prepared TiO2 powder as a photocatalystmaterial under visible light.

scholarly journals Resistivity Enhancement of Sr-Hexaferrite Using Rare Earth Dopant to Minimize Energy Losses

2018 ◽  
Vol 778 ◽  
pp. 195-199 ◽  
Author(s):  
Nahall Niazi ◽  
Omer Farooq ◽  
Fatima Tuz Zahra ◽  
Muhammad Anis-ur-Rehman
Keyword(s):  
Room Temperature ◽  
Single Phase ◽  
Hexagonal Structure ◽  
Precipitation Method ◽  
Strontium Hexaferrite ◽  
Energy Losses ◽  
X Ray Diffraction ◽  
High Frequencies ◽  
X Ray ◽  
Co Precipitation

Strontium hexaferrite is a material of choice due its various magnetic applications. Energy losses are a prominent issue in these magnetic materials. To lower these energy losses, we need to improve the resistivity by reducing eddy current losses. In this work nanoparticles of Gadolinium (Gd) doped Sr-hexaferrite (SrFe12-xGdxO19 x =0 .0, 0.1) have been synthesized by co-precipitation method. Structural analysis was done by using X-ray diffraction technique (XRD). It was found that the formation of single phase i.e. hexagonal structure has been achieved when the samples were sintered at 920°C for 20 minutes. AC electrical properties such as conductivity (𝜎ac), dielectric constant (ε′), dielectric loss (tanδ) and impedance (Z); real (Z') and imaginary (Z") parts have been studied as a function of frequency at room temperature. Aim of the work was to enhance the resistivity and was successfully achieved. Gd doped sample is proposed as an energy efficient material to be used in devices working at high frequencies.

Removal of Formaldehyde Using Mn-Ce-Fe Oxide Catalyst

2013 ◽  
Vol 634-638 ◽  
pp. 567-570
Author(s):  
Hai Zhao ◽  
Ke Jian Han ◽  
Yao Tong ◽  
Xiao Qi Sha ◽  
Yang Yang Li
Keyword(s):  
Room Temperature ◽  
Oxide Catalyst ◽  
Catalytic Performance ◽  
Precipitation Method ◽  
X Ray Diffraction ◽  
Fe Oxide ◽  
X Ray ◽  
Surface Areas ◽  
Transmission Electron ◽  
Co Precipitation

Mn-Ce-Fe Oxide catalysts were prepared by a co-precipitation method using precipitants NH4OH. The catalysts were characterized by Powder X-ray Diffraction (XRD), Transmission Electron Microscopy (TEM) and BET study. It was found that the samples prepared with NH4OH as a precipitator show higher surface areas and sSubscript textuperior catalytic performance at room temperature. The catalysts would reduce substantially indoor formaldehyde concentrations in the present of airstreams.

Microstructures, Electrical and Magnetic Properties of Zn Doped Co Nanoferrites

2012 ◽  
Vol 510-511 ◽  
pp. 221-226 ◽  
Author(s):  
M. Akram ◽  
M. Anis-ur-Rehman ◽  
M. Mubeen ◽  
M. Ali
Keyword(s):  
Magnetic Properties ◽  
Electrical Transport ◽  
Room Temperature ◽  
Precipitation Method ◽  
X Ray Diffraction ◽  
Electrical Transport Properties ◽  
X Ray ◽  
Electrical And Magnetic Properties ◽  
Crystallite Sizes ◽  
Co Precipitation

Non toxicity, bio compatibility and nanometer sizes regime which is comparable to the size of a cell, makes nanocrystalline Co ferrites particles very proficient. In the present research Zn doped cobalt ferrites were prepared by the chemical co-precipitation method and characterized by X-ray diffraction (XRD) at room temperature for structural analysis. X-ray diffraction patterns confirmed the FCC spinel structure of synthesized particles. Crystallite sizes were calculated from the most intense peak (311) using the Debye-Scherrer formula. The obtained crystallite sizes were in nanometer range for all the samples synthesized at reaction temperature of 70°C. Then samples were sintered at 550°C for 2 hours, characterized again by X-ray diffraction at room temperature. The crystallite sizes and lattice constants for all the samples were calculated again from the data obtained by XRD. DC electrical resistivity and AC electrical transport properties were analyzed. The magnetic properties such as coercivity (Hc) and remanence (Mr) of Co1-xZnxFe2O4for x = 0.0, 0.2, 0.4 were measured at room temperature by vibrating sample magnetometer. Coercivity and remanence were found maximum with minimum value of Zn in Co1-xZnxFe2O4.Observed structural and conduction properties of synthesized nanomaterials were correlated.

MICROSTRUCTURE AND MAGNETIC PROPERTIES CHANGE OF Fe3O4 NANOPARTICLES SYNTHESIZED UNDER MAGNETIC FIELDS AT ROOM TEMPERATURE

2009 ◽  
Vol 23 (23) ◽  
pp. 2723-2731 ◽  
Author(s):  
JUN WANG ◽  
SIHUA XIA ◽  
SHIHE CAO
Keyword(s):  
Magnetic Properties ◽  
Magnetic Fields ◽  
Room Temperature ◽  
Precipitation Method ◽  
X Ray Diffraction ◽  
Promising Technique ◽  
X Ray ◽  
Transmission Electron ◽  
Co Precipitation ◽  
Microstructure And Magnetic Properties

Magnetite nanoparticles have been synthesized by a co-precipitation method under magnetic fields (0~1 T) at room temperature. The as-prepared samples were characterized by X-ray diffraction (XRD) and transmission electron microscopy (TEM), vibrating sample magnetometer (VSM) and their microstructure analysis were evaluated on a Mössbauer spectrum. It was found that the Fe 3 O 4 samples produced under a magnetic field of 1 T had a much higher saturation magnetization (15.3 emu/g) than those produced under 0.6 T (7.56 emu/g) and 0 T magnetic fields (6.59 emu/g). This interesting result implies that magnetic fields can affect the growth of Fe 3 O 4 nanoparticles and further change the microstructure and crystallinity of Fe 3 O 4 nanoparticles. It is expected that this process could also be a promising technique to improve the magnetic properties of other magnetic materials.

scholarly journals Thermoluminescence of Undoped and Cu Doped CdS Nanoparticles

2019 ◽  
Vol 9 (1) ◽  
pp. 166-169
Keyword(s):  
Room Temperature ◽  
Precipitation Method ◽  
Cds Nanoparticles ◽  
Particle Sizes ◽  
Hexagonal Crystal Structure ◽  
X Ray Diffraction ◽  
Hexagonal Crystal ◽  
X Ray ◽  
Average Grain Size ◽  
Co Precipitation

In this paper an attempt has been made to synthesize undoped and 1wt% Cu doped CdS nanoparticles through chemical co-precipitation method. Prepared particles were characterized to explore their structural and thermoluminescence properties. The X-ray diffraction analysis reveals a hexagonal crystal structure at room temperature. The particle sizes are determined by Scherer formula for both undoped and doped CdS nanoparticles of various concentrations. The average grain size of undoped and Cu doped nanoparticles is found to be 32.81nm and 22.3nm respectively. The thermoluminescence studies of these above samples show TL peaks occurring at temperatures 379,428,471,510 and 550 Kelvin corresponding to activation energy 0.7 eV, 0.9eV, 1.2 eV, 1.4 eV and 1.3eV respectively.

Mechanical Alloying Behavior in the Nb-Si, Ta-Si, and Nb-Ta-Si Systems

1988 ◽  
Vol 133 ◽  
Author(s):  
K. S. Kumar ◽  
S. K. Mannan
Keyword(s):  
High Temperature ◽  
Mechanical Alloying ◽  
Mechanical Milling ◽  
Room Temperature ◽  
Crystalline Compound ◽  
X Ray Diffraction ◽  
X Ray ◽  
Β Phase ◽  
Α Phase

ABSTRACTThe mechanical alloying behavior of elemental powders in the Nb-Si, Ta-Si, and Nb-Ta-Si systems was examined via X-ray diffraction. The line compounds NbSi2 and TaSi2 form as crystalline compounds rather than amorphous products, but Nb5Si3 and Ta5Si3, although chemically analogous, respond very differently to mechanical milling. The Ta5Si3 composition goes directly from elemental powders to an amorphous product, whereas Nb5Si3 forms as a crystalline compound. The Nb5Si3 compound consists of both the tetragonal room-temperature α phase (c/a = 1.8) and the tetragonal high-temperature β phase (c/a = 0.5). Substituting increasing amounts of Ta for Nb in Nb5Si3 initially stabilizes the α-Nb5Si3 structure preferentially, and subsequently inhibits the formation of a crystalline compound.

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